/* * * Resolver library with GLib integration * * Copyright (C) 2009-2010 Intel Corporation. All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * */ #ifdef HAVE_CONFIG_H #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include "gresolv.h" struct sort_result { int precedence; int src_scope; int dst_scope; int src_label; int dst_label; gboolean reachable; union { struct sockaddr sa; struct sockaddr_in sin; struct sockaddr_in6 sin6; } src; union { struct sockaddr sa; struct sockaddr_in sin; struct sockaddr_in6 sin6; } dst; }; struct resolv_query; struct resolv_lookup { GResolv *resolv; guint id; int nr_results; struct sort_result *results; struct resolv_query *ipv4_query; struct resolv_query *ipv6_query; guint ipv4_status; guint ipv6_status; GResolvResultFunc result_func; gpointer result_data; }; struct resolv_query { GResolv *resolv; guint timeout; uint16_t msgid; struct resolv_lookup *lookup; }; struct resolv_nameserver { GResolv *resolv; char *address; uint16_t port; unsigned long flags; GIOChannel *udp_channel; guint udp_watch; }; struct _GResolv { int ref_count; int result_family; guint next_lookup_id; GQueue *lookup_queue; GQueue *query_queue; int index; GList *nameserver_list; struct __res_state res; GResolvDebugFunc debug_func; gpointer debug_data; }; static inline void debug(GResolv *resolv, const char *format, ...) { char str[256]; va_list ap; if (resolv->debug_func == NULL) return; va_start(ap, format); if (vsnprintf(str, sizeof(str), format, ap) > 0) resolv->debug_func(str, resolv->debug_data); va_end(ap); } static void destroy_query(struct resolv_query *query) { if (query->timeout > 0) g_source_remove(query->timeout); g_free(query); } static void destroy_lookup(struct resolv_lookup *lookup) { if (lookup->ipv4_query != NULL) { g_queue_remove(lookup->resolv->query_queue, lookup->ipv4_query); destroy_query(lookup->ipv4_query); } if (lookup->ipv6_query != NULL) { g_queue_remove(lookup->resolv->query_queue, lookup->ipv6_query); destroy_query(lookup->ipv6_query); } g_free(lookup->results); g_free(lookup); } static void find_srcaddr(struct sort_result *res) { socklen_t sl = sizeof(res->src); int fd; fd = socket(res->dst.sa.sa_family, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_IP); if (fd < 0) return; if (connect(fd, &res->dst.sa, sizeof(res->dst)) < 0) { close(fd); return; } if (getsockname(fd, &res->src.sa, &sl) < 0) { close(fd); return; } res->reachable = TRUE; close(fd); } struct gai_table { unsigned char addr[NS_IN6ADDRSZ]; int mask; int value; }; static const struct gai_table gai_labels[] = { { .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 }, .mask = 128, .value = 0, }, { .addr = { 0x20, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, .mask = 16, .value = 2, }, { .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, .mask = 96, .value = 3, }, { .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00 }, .mask = 96, .value = 4, }, { /* Variations from RFC 3484, matching glibc behaviour */ .addr = { 0xfe, 0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, .mask = 10, .value = 5, }, { .addr = { 0xfc, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, .mask = 7, .value = 6, }, { .addr = { 0x20, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, .mask = 32, .value = 7, }, { /* catch-all */ .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, .mask = 0, .value = 1, } }; static const struct gai_table gai_precedences[] = { { .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 }, .mask = 128, .value = 50, }, { .addr = { 0x20, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, .mask = 16, .value = 30, }, { .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, .mask = 96, .value = 20, }, { .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00 }, .mask = 96, .value = 10, }, { .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, .mask = 0, .value = 40, } }; static unsigned char v4mapped[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00 }; static gboolean mask_compare(const unsigned char *one, const unsigned char *two, int mask) { if (mask > 8) { if (memcmp(one, two, mask / 8)) return FALSE; one += mask / 8; two += mask / 8; mask %= 8; } if (mask && ((*one ^ *two) >> (8 - mask))) return FALSE; return TRUE; } static int match_gai_table(struct sockaddr *sa, const struct gai_table *tbl) { struct sockaddr_in *sin = (void *)sa; struct sockaddr_in6 *sin6 = (void *)sa; void *addr; if (sa->sa_family == AF_INET) { addr = v4mapped; memcpy(v4mapped+12, &sin->sin_addr, NS_INADDRSZ); } else addr = &sin6->sin6_addr; while (1) { if (mask_compare(addr, tbl->addr, tbl->mask)) return tbl->value; tbl++; } } #define DQUAD(_a,_b,_c,_d) ( ((_a)<<24) | ((_b)<<16) | ((_c)<<8) | (_d) ) #define V4MATCH(addr, a,b,c,d, m) ( ((addr) ^ DQUAD(a,b,c,d)) >> (32 - (m)) ) #define RFC3484_SCOPE_LINK 2 #define RFC3484_SCOPE_SITE 5 #define RFC3484_SCOPE_GLOBAL 14 static int addr_scope(struct sockaddr *sa) { if (sa->sa_family == AF_INET) { struct sockaddr_in *sin = (void *)sa; guint32 addr = ntohl(sin->sin_addr.s_addr); if (V4MATCH(addr, 169,254,0,0, 16) || V4MATCH(addr, 127,0,0,0, 8)) return RFC3484_SCOPE_LINK; /* Site-local */ if (V4MATCH(addr, 10,0,0,0, 8) || V4MATCH(addr, 172,16,0,0, 12) || V4MATCH(addr, 192,168,0,0, 16)) return RFC3484_SCOPE_SITE; /* Global */ return RFC3484_SCOPE_GLOBAL; } else { struct sockaddr_in6 *sin6 = (void *)sa; /* Multicast addresses have a 4-bit scope field */ if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) return sin6->sin6_addr.s6_addr[1] & 0xf; if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr) || IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) return RFC3484_SCOPE_LINK; if (IN6_IS_ADDR_SITELOCAL(&sin6->sin6_addr)) return RFC3484_SCOPE_SITE; return RFC3484_SCOPE_GLOBAL; } } static int rfc3484_compare(const void *__one, const void *__two) { const struct sort_result *one = __one; const struct sort_result *two = __two; /* Rule 1: Avoid unusable destinations */ if (one->reachable && !two->reachable) return -1; else if (two->reachable && !one->reachable) return 1; /* Rule 2: Prefer matching scope */ if (one->dst_scope == one->src_scope && two->dst_scope != two->src_scope) return -1; else if (two->dst_scope == two->src_scope && one->dst_scope != one->src_scope) return 1; /* Rule 3: Avoid deprecated addresses */ /* Rule 4: Prefer home addresses */ /* Rule 5: Prefer matching label */ if (one->dst_label == one->src_label && two->dst_label != two->src_label) return -1; else if (two->dst_label == two->src_label && one->dst_label != one->src_label) return 1; /* Rule 6: Prefer higher precedence */ if (one->precedence > two->precedence) return -1; else if (two->precedence > one->precedence) return 1; /* Rule 7: Prefer native transport */ /* Rule 8: Prefer smaller scope */ if (one->dst_scope != two->dst_scope) return one->dst_scope - two->dst_scope; /* Rule 9: Use longest matching prefix */ if (one->dst.sa.sa_family == AF_INET) { /* * Rule 9 is meaningless and counterproductive for Legacy IP * unless perhaps we can tell that it's actually on the local * subnet. But we don't (yet) have local interface config * information, so do nothing here for Legacy IP for now. */ } else { int i; for (i = 0; i < 4; i++) { guint32 cmp_one, cmp_two; cmp_one = one->src.sin6.sin6_addr.s6_addr32[i] ^ one->dst.sin6.sin6_addr.s6_addr32[i]; cmp_two = two->src.sin6.sin6_addr.s6_addr32[i] ^ two->dst.sin6.sin6_addr.s6_addr32[i]; if (!cmp_two && !cmp_one) continue; if (cmp_one && !cmp_two) return 1; if (cmp_two && !cmp_one) return -1; /* g_bit_storage() is effectively fls() */ cmp_one = g_bit_storage(ntohl(cmp_one)); cmp_two = g_bit_storage(ntohl(cmp_two)); if (cmp_one == cmp_two) break; return cmp_one - cmp_two; } } /* Rule 10: Otherwise, leave the order unchanged */ if (one < two) return -1; else return 1; } static void rfc3484_sort_results(struct resolv_lookup *lookup) { int i; for (i = 0; i < lookup->nr_results; i++) { struct sort_result *res = &lookup->results[i]; find_srcaddr(res); res->precedence = match_gai_table(&res->dst.sa, gai_precedences); res->dst_label = match_gai_table(&res->dst.sa, gai_labels); res->src_label = match_gai_table(&res->src.sa, gai_labels); res->dst_scope = addr_scope(&res->dst.sa); res->src_scope = addr_scope(&res->src.sa); } qsort(lookup->results, lookup->nr_results, sizeof(struct sort_result), rfc3484_compare); } static void sort_and_return_results(struct resolv_lookup *lookup) { char buf[INET6_ADDRSTRLEN + 1]; GResolvResultStatus status; char **results = g_try_new0(char *, lookup->nr_results + 1); int i, n = 0; if (!results) return; memset(buf, 0, INET6_ADDRSTRLEN + 1); rfc3484_sort_results(lookup); for (i = 0; i < lookup->nr_results; i++) { if (lookup->results[i].dst.sa.sa_family == AF_INET) { if (inet_ntop(AF_INET, &lookup->results[i].dst.sin.sin_addr, buf, sizeof(buf) - 1) == NULL) continue; } else if (lookup->results[i].dst.sa.sa_family == AF_INET6) { if (inet_ntop(AF_INET6, &lookup->results[i].dst.sin6.sin6_addr, buf, sizeof(buf) - 1) == NULL) continue; } else continue; results[n++] = strdup(buf); } results[n++] = NULL; status = lookup->ipv4_status; if (status == G_RESOLV_RESULT_STATUS_SUCCESS) status = lookup->ipv6_status; lookup->result_func(status, results, lookup->result_data); g_strfreev(results); g_queue_remove(lookup->resolv->lookup_queue, lookup); destroy_lookup(lookup); } static gboolean query_timeout(gpointer user_data) { struct resolv_query *query = user_data; struct resolv_lookup *lookup = query->lookup; GResolv *resolv = query->resolv; query->timeout = 0; if (query == lookup->ipv4_query) { lookup->ipv4_status = G_RESOLV_RESULT_STATUS_NO_RESPONSE; lookup->ipv4_query = NULL; } else if (query == lookup->ipv6_query) { lookup->ipv6_status = G_RESOLV_RESULT_STATUS_NO_RESPONSE; lookup->ipv6_query = NULL; } if (lookup->ipv4_query == NULL && lookup->ipv4_query == NULL) sort_and_return_results(lookup); destroy_query(query); g_queue_remove(resolv->query_queue, query); return FALSE; } static void free_nameserver(struct resolv_nameserver *nameserver) { if (nameserver == NULL) return; if (nameserver->udp_watch > 0) g_source_remove(nameserver->udp_watch); if (nameserver->udp_channel != NULL) g_io_channel_unref(nameserver->udp_channel); g_free(nameserver->address); g_free(nameserver); } static void flush_nameservers(GResolv *resolv) { GList *list; for (list = g_list_first(resolv->nameserver_list); list; list = g_list_next(list)) free_nameserver(list->data); g_list_free(resolv->nameserver_list); resolv->nameserver_list = NULL; } static int send_query(GResolv *resolv, const unsigned char *buf, int len) { GList *list; if (resolv->nameserver_list == NULL) return -ENOENT; for (list = g_list_first(resolv->nameserver_list); list; list = g_list_next(list)) { struct resolv_nameserver *nameserver = list->data; int sk, sent; if (nameserver->udp_channel == NULL) continue; sk = g_io_channel_unix_get_fd(nameserver->udp_channel); sent = send(sk, buf, len, 0); if (sent < 0) continue; } return 0; } static gint compare_lookup_id(gconstpointer a, gconstpointer b) { const struct resolv_lookup *lookup = a; guint id = GPOINTER_TO_UINT(b); if (lookup->id < id) return -1; if (lookup->id > id) return 1; return 0; } static gint compare_query_msgid(gconstpointer a, gconstpointer b) { const struct resolv_query *query = a; uint16_t msgid = GPOINTER_TO_UINT(b); if (query->msgid < msgid) return -1; if (query->msgid > msgid) return 1; return 0; } static void add_result(struct resolv_lookup *lookup, int family, const void *data) { int n = lookup->nr_results++; lookup->results = g_realloc(lookup->results, sizeof(struct sort_result) * (n + 1)); memset(&lookup->results[n], 0, sizeof(struct sort_result)); lookup->results[n].dst.sa.sa_family = family; if (family == AF_INET) memcpy(&lookup->results[n].dst.sin.sin_addr, data, NS_INADDRSZ); else memcpy(&lookup->results[n].dst.sin6.sin6_addr, data, NS_IN6ADDRSZ); } static void parse_response(struct resolv_nameserver *nameserver, const unsigned char *buf, int len) { GResolv *resolv = nameserver->resolv; GResolvResultStatus status; struct resolv_query *query; struct resolv_lookup *lookup; GList *list; ns_msg msg; ns_rr rr; int i, rcode, count; debug(resolv, "response from %s", nameserver->address); ns_initparse(buf, len, &msg); rcode = ns_msg_getflag(msg, ns_f_rcode); count = ns_msg_count(msg, ns_s_an); debug(resolv, "msg id: 0x%04x rcode: %d count: %d", ns_msg_id(msg), rcode, count); switch (rcode) { case 0: status = G_RESOLV_RESULT_STATUS_SUCCESS; break; case 1: status = G_RESOLV_RESULT_STATUS_FORMAT_ERROR; break; case 2: status = G_RESOLV_RESULT_STATUS_SERVER_FAILURE; break; case 3: status = G_RESOLV_RESULT_STATUS_NAME_ERROR; break; case 4: status = G_RESOLV_RESULT_STATUS_NOT_IMPLEMENTED; break; case 5: status = G_RESOLV_RESULT_STATUS_REFUSED; break; default: status = G_RESOLV_RESULT_STATUS_ERROR; break; } list = g_queue_find_custom(resolv->query_queue, GUINT_TO_POINTER(ns_msg_id(msg)), compare_query_msgid); if (!list) return; query = list->data; lookup = query->lookup; if (query == lookup->ipv6_query) { lookup->ipv6_status = status; lookup->ipv6_query = NULL; } else if (query == lookup->ipv4_query) { lookup->ipv4_status = status; lookup->ipv4_query = NULL; } for (i = 0; i < count; i++) { ns_parserr(&msg, ns_s_an, i, &rr); if (ns_rr_class(rr) != ns_c_in) continue; g_assert(offsetof(struct sockaddr_in, sin_addr) == offsetof(struct sockaddr_in6, sin6_flowinfo)); if (ns_rr_type(rr) == ns_t_a && ns_rr_rdlen(rr) == NS_INADDRSZ) { add_result(lookup, AF_INET, ns_rr_rdata(rr)); } else if (ns_rr_type(rr) == ns_t_aaaa && ns_rr_rdlen(rr) == NS_IN6ADDRSZ) { add_result(lookup, AF_INET6, ns_rr_rdata(rr)); } } if (lookup->ipv4_query == NULL && lookup->ipv6_query == NULL) sort_and_return_results(lookup); destroy_query(query); g_queue_remove(resolv->query_queue, query); } static gboolean received_udp_data(GIOChannel *channel, GIOCondition cond, gpointer user_data) { struct resolv_nameserver *nameserver = user_data; unsigned char buf[4096]; int sk, len; if (cond & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) { nameserver->udp_watch = 0; return FALSE; } sk = g_io_channel_unix_get_fd(nameserver->udp_channel); len = recv(sk, buf, sizeof(buf), 0); if (len < 12) return TRUE; parse_response(nameserver, buf, len); return TRUE; } static int connect_udp_channel(struct resolv_nameserver *nameserver) { struct addrinfo hints, *rp; char portnr[6]; int err, sk; memset(&hints, 0, sizeof(hints)); hints.ai_family = AF_UNSPEC; hints.ai_socktype = SOCK_DGRAM; hints.ai_flags = AI_PASSIVE | AI_NUMERICSERV | AI_NUMERICHOST; sprintf(portnr, "%d", nameserver->port); err = getaddrinfo(nameserver->address, portnr, &hints, &rp); if (err) return -EINVAL; /* * Do not blindly copy this code elsewhere; it doesn't loop over the * results using ->ai_next as it should. That's OK in *this* case * because it was a numeric lookup; we *know* there's only one. */ if (!rp) return -EINVAL; sk = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol); if (sk < 0) { freeaddrinfo(rp); return -EIO; } /* * If nameserver points to localhost ip, their is no need to * bind the socket on any interface. */ if (nameserver->resolv->index > 0 && strncmp(nameserver->address, "127.0.0.1", 9) != 0) { char interface[IF_NAMESIZE]; memset(interface, 0, IF_NAMESIZE); if (if_indextoname(nameserver->resolv->index, interface) != NULL) { if (setsockopt(sk, SOL_SOCKET, SO_BINDTODEVICE, interface, IF_NAMESIZE) < 0) { close(sk); freeaddrinfo(rp); return -EIO; } } } if (connect(sk, rp->ai_addr, rp->ai_addrlen) < 0) { close(sk); freeaddrinfo(rp); return -EIO; } freeaddrinfo(rp); nameserver->udp_channel = g_io_channel_unix_new(sk); if (nameserver->udp_channel == NULL) { close(sk); return -ENOMEM; } g_io_channel_set_close_on_unref(nameserver->udp_channel, TRUE); nameserver->udp_watch = g_io_add_watch(nameserver->udp_channel, G_IO_IN | G_IO_NVAL | G_IO_ERR | G_IO_HUP, received_udp_data, nameserver); return 0; } GResolv *g_resolv_new(int index) { GResolv *resolv; if (index < 0) return NULL; resolv = g_try_new0(GResolv, 1); if (resolv == NULL) return NULL; resolv->ref_count = 1; resolv->result_family = AF_UNSPEC; resolv->next_lookup_id = 1; resolv->query_queue = g_queue_new(); if (resolv->query_queue == NULL) { g_free(resolv); return NULL; } resolv->lookup_queue = g_queue_new(); if (resolv->lookup_queue == NULL) { g_queue_free(resolv->query_queue); g_free(resolv); return NULL; } resolv->index = index; resolv->nameserver_list = NULL; res_ninit(&resolv->res); return resolv; } GResolv *g_resolv_ref(GResolv *resolv) { if (resolv == NULL) return NULL; __sync_fetch_and_add(&resolv->ref_count, 1); return resolv; } void g_resolv_unref(GResolv *resolv) { struct resolv_query *query; if (resolv == NULL) return; if (__sync_fetch_and_sub(&resolv->ref_count, 1) != 1) return; while ((query = g_queue_pop_head(resolv->query_queue))) destroy_query(query); g_queue_free(resolv->query_queue); g_queue_free(resolv->lookup_queue); flush_nameservers(resolv); res_nclose(&resolv->res); g_free(resolv); } void g_resolv_set_debug(GResolv *resolv, GResolvDebugFunc func, gpointer user_data) { if (resolv == NULL) return; resolv->debug_func = func; resolv->debug_data = user_data; } gboolean g_resolv_add_nameserver(GResolv *resolv, const char *address, uint16_t port, unsigned long flags) { struct resolv_nameserver *nameserver; if (resolv == NULL) return FALSE; nameserver = g_try_new0(struct resolv_nameserver, 1); if (nameserver == NULL) return FALSE; nameserver->address = g_strdup(address); nameserver->port = port; nameserver->flags = flags; nameserver->resolv = resolv; if (connect_udp_channel(nameserver) < 0) { free_nameserver(nameserver); return FALSE; } resolv->nameserver_list = g_list_append(resolv->nameserver_list, nameserver); debug(resolv, "setting nameserver %s", address); return TRUE; } void g_resolv_flush_nameservers(GResolv *resolv) { if (resolv == NULL) return; flush_nameservers(resolv); } static gint add_query(struct resolv_lookup *lookup, const char *hostname, int type) { struct resolv_query *query = g_try_new0(struct resolv_query, 1); unsigned char buf[4096]; int len; if (query == NULL) return -ENOMEM; len = res_mkquery(ns_o_query, hostname, ns_c_in, type, NULL, 0, NULL, buf, sizeof(buf)); query->msgid = buf[0] << 8 | buf[1]; if (send_query(lookup->resolv, buf, len) < 0) { g_free(query); return -EIO; } query->resolv = lookup->resolv; query->lookup = lookup; g_queue_push_tail(lookup->resolv->query_queue, query); query->timeout = g_timeout_add_seconds(5, query_timeout, query); if (type == ns_t_aaaa) lookup->ipv6_query = query; else lookup->ipv4_query = query; return 0; } guint g_resolv_lookup_hostname(GResolv *resolv, const char *hostname, GResolvResultFunc func, gpointer user_data) { struct resolv_lookup *lookup; debug(resolv, "lookup hostname %s", hostname); if (resolv == NULL) return 0; if (resolv->nameserver_list == NULL) { int i; for (i = 0; i < resolv->res.nscount; i++) { char buf[100]; int family = resolv->res.nsaddr_list[i].sin_family; void *sa_addr = &resolv->res.nsaddr_list[i].sin_addr; if (family != AF_INET && resolv->res._u._ext.nsaddrs[i]) { family = AF_INET6; sa_addr = &resolv->res._u._ext.nsaddrs[i]->sin6_addr; } if (family != AF_INET && family != AF_INET6) continue; if (inet_ntop(family, sa_addr, buf, sizeof(buf))) g_resolv_add_nameserver(resolv, buf, 53, 0); } if (resolv->nameserver_list == NULL) g_resolv_add_nameserver(resolv, "127.0.0.1", 53, 0); } lookup = g_try_new0(struct resolv_lookup, 1); if (lookup == NULL) return 0; lookup->resolv = resolv; lookup->result_func = func; lookup->result_data = user_data; lookup->id = resolv->next_lookup_id++; if (resolv->result_family != AF_INET6) { if (add_query(lookup, hostname, ns_t_a)) { g_free(lookup); return -EIO; } } if (resolv->result_family != AF_INET) { if (add_query(lookup, hostname, ns_t_aaaa)) { if (resolv->result_family != AF_INET6) { destroy_query(lookup->ipv4_query); g_queue_remove(resolv->query_queue, lookup->ipv4_query); } g_free(lookup); return -EIO; } } g_queue_push_tail(resolv->lookup_queue, lookup); return lookup->id; } gboolean g_resolv_cancel_lookup(GResolv *resolv, guint id) { GList *list; list = g_queue_find_custom(resolv->lookup_queue, GUINT_TO_POINTER(id), compare_lookup_id); if (list == NULL) return FALSE; destroy_lookup(list->data); g_queue_remove(resolv->query_queue, list->data); return TRUE; } gboolean g_resolv_set_address_family(GResolv *resolv, int family) { if (resolv == NULL) return FALSE; if (family != AF_UNSPEC && family != AF_INET && family != AF_INET6) return FALSE; resolv->result_family = family; return TRUE; }